I can only say that I need something like the ballmount setup above. My current system looks more like DBs old fish finder attachments....there has to be a better way...time for me to start shopping RAM mounts again.

Thanks to Arnesr, I now have one of these attached  to my Eagle Cuda 168.  This unit is not fancy,  (with a B&W only screen) but it draws so little power that I can run it on 8 AA bats for a two week trip and still have plenty of juice at the end. 

So this computer printed appliance will joint the computer printed appliance in my skull on my next trip!   

There is something nostalgic about these old black and white fish finders.  In some ways they are outdated, but still very useful and efficient at what they do if you can find one of the later models. On the other hand, I also have a few old flasher units laying around as well as what was my folks wall mounted rotary phone, all still operable, but I wouldn't want to have to use either of them.   

I am glad some have found the ball mounts useful.  It is definitely a niche item.

HighNDry, I may have a solution for you if you are willing to be a beta tester.  I have an old Humminbird Piranha model 2, circa 2004 that I used to use with AA batteries.  I modeled a ball mount adapter for it which may or may not fit your P175 unit.  It is a simpler design as Humminbird basically uses a small gimble bracket with two screws to tighten the screen to the base.  My design fits over the bracket and secures with a 10-24 bolt, then there is a 1/4 inch bolt going through the balll and a lock nut as in my other design. 
(You need to Login or Register to view media files and links) (You need to Login or Register to view media files and links)

I can help you out with the power connection too, as it was a project I was working on already.   I have a 3 piece 3D printed two pin power plug that I designed.  I have a Helix unit that I got with a boat I purchased, and I was surprised it used the exact same power plug as my old Piranha unit.  I have been trying to incorporate these 5.5mm quick disconnect plugs on my units as they work quite well.  These connections are commonly used for low voltage LED lighting applications, so they are quite common and you can get extensions in a variety of increments.  The plugs aren't submersible waterproof, but I try not to operate in submarine mode and they have been fine out in the rain.

(You need to Login or Register to view media files and links)


Here is my 3D printed Lowrance Power plug for comparison.  This won't fit the B&W units such as the X-4 or Cuda units, as they use a different molded connector integrated with the transducer.  The newer Hook2 and Hook Reveal units also use a different molded push in connector. 

(You need to Login or Register to view media files and links)

Rather than use a purpose-made gimble mount  for a depth finder, I decided to go with a more general-purpose  option. 

I found this choice on  Amazon. (You need to Login or Register to view media files and links)

It was designed to hold a camera (e.g., GoPro), but by swapping out the ball mount for the camera with the one for the depth finder, I have a solution that winds up being multi-purpose.    Of course, the base plate mount on the mount is replaced with a clamp that has its own ball mount.  Since I tend to rent canoes rather than transporting them 1000 miles each direction, I needed a "non-permanent" option.  This should be perfect for attaching to a thwart.

Beyond that, I how have a place to mount my iPhone.  Not only do I sue it with my inReach for communication purposes, my phone also has a number of maps of Quetico (e.g, Canada Topo, Garman, Gaia), that I take along.  They are more for reference purposes and used in addition to my printed maps, but non-the-less helpful.  So I've removed the GoPro style mount from the original top which leaves a threaded camera mount on top of a 1-inch ball.  I attached that to a swiveling cell phone mount.

So on fishing days, I'll mount the depth finder.  For travel days, I'll mount my iphone and with my bluetooth  remote, I can take photos while I travel.

dd

That is a clever idea.  I have been using a separate mount for my Garmin unit and one for my fish finder.  I could probably get away with swapping them, which I had not considered.  My Garmin is currently rigged up with a similar clamp on system as yours, but my fish finder is rigged with a u bolt mount, not permanent, but it takes a bit more effort to remove.